Reuben with sauce

salt 1 lb cavatappi pasta , hallow corkscrew shaped pasta or, other short cut 2 slices rye bread 3 tablespoons butter , plus some butter , for buttering toast[...]

3 tablespoons unsalted butter 1 onion , finely chopped 1 cup cooked ham , finely chopped 1 1/2 cups corned beef , finely chopped 1/2 garlic clove , crushed 2[...]